Depends which coatings you're referring to. Polished Ceramic on SS is still going to be limited to the temp restrictions, but it wont weep rust when it fails if you do. High Temp Ceramics on SS will pretty much last forever..... Most modern performance cars i.e. Challenger, Charger, Corvette, Camaro, Mustang, etc use either Kooks, ARH or Stainless Works headers which are all made from SS exclusively.